Allow building the website for a single example

`nox -e example` will build example and then the website,
`nox -e docs` will build all examples and the website at the end

.gitignore

@@ -2,6 +2,5 @@ docs/src/examples/
 
 *build*
 *egg-info/
-sg_execution_times.rst
 
 .nox/

docs/src/.gitignore

@@ -0,0 +1,2 @@
+sg_execution_times.rst
+index.rst

docs/src/index.rst.in

@@ -0,0 +1,6 @@
+COSMO Software Cookbook
+=======================
+
+.. include:: ../../README.rst
+   :start-after: marker-intro-start
+   :end-before: marker-intro-end

noxfile.py

@@ -95,13 +95,17 @@ def example(session, name=name):
         session.run("python", "generate-gallery.py", f"examples/{name}")
         os.unlink(f"docs/src/examples/{name}/index.rst")
 
+        if "--no-build-docs" not in session.posargs:
+            session.notify("build_docs")
+
 
 @nox.session(venv_backend="none")
 def docs(session):
     """Run all examples and build the documentation"""
 
     for example in EXAMPLES:
-        session.run("nox", "-e", example, external=True)
+        session.run("nox", "-e", example, "--", "--no-build-docs", external=True)
+
     session.run("nox", "-e", "build_docs", external=True)
 
 
@@ -113,6 +117,21 @@ def build_docs(session):
     if should_reinstall_dependencies(session, requirements=requirements):
         session.install("-r", requirements)
 
+    with open("docs/src/index.rst", "w") as output:
+        with open("docs/src/index.rst.in") as fd:
+            output.write(fd.read())
+
+        output.write(".. toctree::\n")
+        output.write("    :caption: Table of Contents\n")
+        output.write("    :maxdepth: 1\n")
+        output.write("\n")
+
+        for file in glob.glob("docs/src/examples/*/*.rst"):
+            if os.path.basename(file) != "sg_execution_times.rst":
+                path = file[9:-4]
+
+                output.write(f"    {path}\n")
+
     session.run("sphinx-build", "-W", "-b", "html", "docs/src", "docs/build/html")